import java.util.Locale;
import java.util.Scanner;

public class Test {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int a = in.nextInt();//3  = 2
            int num=0;
            if (a == 1 && a == 2) {
                System.out.println(1);
            }
            for (int i = 3; i <= a; i++) {
                num=(i-1)+(i-2);
            }
        }
    }

    public static void main3(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            char a = (char)in.nextInt();
            in.nextLine();
            char b = (char)in.nextInt();

            if (a > 'A' && a < 'Z') {
                a -= 32;
            }
            if (b > 'A' && b < 'Z') {
                b -= 32;
            }
            System.out.println(a);
            System.out.println(b);
        }
    }


    @Override
    public String toString() {
        return super.toString();
    }

    public static void main2(String[] args) {
        int[] name= {1,2,3,4};

        System.out.println(name.toString());

    }

   /* public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            char a = in.hasNext();
            in.nextLine();
            char b = (char)in.nextInt();

            if (a > 'A' && a < 'Z') {
                a += 32;
            }
            if (b > 'A' && b < 'Z') {
                b += 32;
            }
            System.out.println(a);
            System.out.println(b);
        }
    }*/
}
